GREEN, RAPID, SIMPLE, AND AN EFFECTIVE ONE-POT MULTICOMPONENT STRATEGY FOR SYNTHESIS OF NOVEL DIHYDROPYRANO[2,3-C]PYRAZOL-6-AMINES IN AQUEOUS MEDIUM
Objectives: A series of new dihydropyrano [2,3-c]pyrazol-6-amines in this investigation study, are synthesized by the strategy of one-pot four component reaction in an aqueous medium.
Methods: After getting optimum conditions the reaction of different substituted aromatic aldehydes, ethyl acetoacetate, hydrazine hydrate, and phenylacetonitrile catalysed by Sodium hydrogen sulphate NaHSO4 (0.5 m mol) by refluxing in ethanol-water (1:1) (5 ml) and heated at 80 oC. The synthesized molecules product was filtered, washed with water to get nearly pure product in excellent yield.
Results: The pure products which were got in a short duration, with excellent yield (80 – 87%). Those new compounds were identified by using spectroscopic techniques FT-IR, 1H-NMR and 13C-NMR.
Conclusion: In conclusion, the usefulness of this one-pot multicomponents protocol include easily available starting materials, facile, simple and environment-friendly procedure, and easier separation of products by filtration.
Peer Review History:
Received 5 March 2019; Revised 11 April; Accepted 9 May, Available online 15 May 2020
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Average Peer review marks at initial stage: 5.0/10
Average Peer review marks at publication stage: 7.0/10
Name: Prof Cyprian Ogbonna ONYEJI
Affiliation: Obafemi Awolowo University, Ile-Ife, Nigeria
Name: Dr. Md. Shahidul Islam
Affiliation: USTC, Chittagong, Bangladesh
Comments of reviewer(s):